Organic Light Emitting Diode (OLED) is a flat panel display technology which has great prospects for development. It does not only possess extremely excellent display performance but also properties of self-illumination, simple structure, ultra thin, fast response speed, wide view angle, low power consumption and capability of realizing flexible display, and therefore is considered as “dream display”. Meanwhile, the investment for the production equipments is far smaller than the Liquid Crystal Display (LCD). It has been favored by respective big display makers and has become the main selection of the third generation display element.
As shown in FIG. 1, it is a drive circuit diagram of an OLED according to prior art. In the OLED display device, each OLED element can be equivalent to a structure having a light emitting diode and a capacitor coupled in parallel, and the size of the capacitor coupled in parallel directly influences the voltage of two ends, the flowing through current value of the OLED, and accordingly influences the display quality of the entire OLED display device.
As shown in FIG. 2, it is a sectional diagram of an OLED pixel structure according to prior art. The OLED pixel structure comprises red, green, blue sub pixel areas, and the red, the green, the blue sub pixel areas respectively comprise a substrate 100, an anode 200 formed on the substrate 100, a flat layer 300 formed on the anode 200, an organic light emitting layer 400 formed on the flat layer 300 and a cathode 500 formed on the organic light emitting layer 400, and an aperture area 310 is formed on the flat layer 300, and the organic light emitting layer 400 contacts the anode 200 through the aperture area 310.
In the OLED pixel structure according to prior art, the light emitting materials, the aperture ratios and attenuations of the red, the green, the blue sub pixel areas are different and the total capacitance values of the red, the green, the blue sub pixel areas are different. Thus, the voltages of two ends of the OLEDs in the different sub pixel areas are different, and the brightnesses of the OLEDs in the different sub pixel areas are different, either. Accordingly, the performances of the OLED elements and the display quality of the entire display screen are influenced.